Recent Timeline:May 22, 1990 - The Republic of Yemen is created from the unification of North Yemen, the Yemen Arab Republic and South Yemen, the People's Democratic Republic of Yemen.

May-July 1994 - A civil war between northerners and southerners begins due to disagreements between supporters of President Ali Abdullah Saleh, from North Yemen, and Vice President Ali Salim al-Baid, from South Yemen. Troops loyal to President Saleh win the war.

September 25, 1999 - Saleh wins the country's first direct presidential election, with 96.3% of the vote. Opposition leaders allege tampering at the ballot box.

September 23, 2006 - Saleh wins re-election to a seven-year term with 77% of the vote.

September 17, 2008 - Ten people are killed in terrorist attack on the US embassy in Sanaa. The victims are Yemeni citizens and police officers.

January 2, 2010 -US President Barack Obama announces a new counterterrorism partnership with Yemen, involving intelligence sharing, military training and joint attacks.

January 3, 2010 - The United States and the United Kingdom temporarily close their embassies in Sanaa after they receive word that AQAP may be planning an attack on the facilities. The US embassy reopens two days later after Yemeni forces kill two AQAP militants in a counterterrorism operation.

January 2010 - A group called Friends of Yemen is established in the United Kingdom to rally support for Yemen from the international community. They later hold meetings in London and Saudi Arabia.

February 10, 2014 - State news reports that Hadi has approved making Yemen a federal state consisting of six regions: two in the south, and four in the north. Sanaa is designated as neutral territory.

September 21, 2014 - Hadi, Houthi rebels and representatives of major political parties sign a ceasefire deal. The United Nations-brokered deal ends a month of protests by Houthis that essentially halted life in Sanaa and resulted in hundreds of people being killed or injured.

January 17, 2015 - Houthi rebels kidnap Hadi's Chief of Staff Ahmed bin Mubarak in a push for more political power. He is released 10 days later, according to Reuters.

January 20, 2015 - Houthi rebels take over the presidential palace.

January 22, 2015 - President Hadi resigns shortly after the prime minister and the cabinet step down. Houthis say they will withdraw their fighters from Sanaa if the government agrees to constitutional changes including fair representation for marginalized groups within the country. No agreement is reached.

February 11, 2015 - The United States and the United Kingdom suspend embassy operations in Yemen.

March 20, 2015 - Terrorists bomb two mosques in Sanaa, killing at least 137 and wounding 357. ISIS claims responsibility for the attack.

December 18-19, 2015 - At least 100 people are killed as violence erupts in the Harath district of Hajjah, a strategic border near Saudi Arabia.

November 28, 2016 - The Iranian-backed Houthi movement forms a new government in the capital. Abdul Aziz Habtoor, who defected from Hadi's government and joined the Houthi coalition in 2015, is its leader, according to the movement's news agency Saba.

December 18, 2016 - A suicide bomber strikes as soldiers line up to receive their salaries at the Al Solban military base in the southern city of Aden. The strike kills at least 52 soldiers and injures 34 others, two Yemeni senior security officials tell CNN. ISIS claims responsibility.

January 29, 2017 - US Central Command announces that a Navy SEAL was killed during a raid on a suspected al Qaeda hideout in a Yemeni village. The Navy SEAL is later identified as William Owens. The Pentagon reports that 14 terrorists were killed during the raid. Yemeni officials say civilians got caught in the crossfire and 13 people died, including 8-year-old Nawar Anwar Al-Awalki, the daughter of Anwar Al-Awalki. The raid was authorized by US President Donald Trump, days after he was sworn in as commander in chief.

December 21, 2017 - The International Committee of the Red Cross announces that one million cases of cholera have been reported in Yemen since the outbreak began during the spring. More than 2,200 people have died, according to the World Health Organization. It is the largest outbreak of the disease in recent history.